The present invention relates to a band control system, a band control apparatus and a communication apparatus, and for example, can be applied to a band control system, a band control apparatus and a communication apparatus which use a time division multiplex-passive optical network (TDM-PON) system.
In recent years, in order to accommodate rapidly increasing mobile traffic, a configuration has been studied in which a number of radio base stations (also referred to as so-called “small cells”) having narrower cover areas than that of a radio base station in related art are provided to improve throughput per unit area.
The small cell is configured with a base band processing unit (base band unit (BBU)) and a remote radio transmitting/receiving unit (remote radio head (RRH)).
The BBU modulates a packet signal from an upper network and transmits the modulated signal to the RRH, or demodulates a signal from the RRH to packetize the signal and transmits the packetized signal to the upper network. Further, the RRH transmits a signal from an antenna connected in a subsequent stage to user equipment (UE), or transmits a signal received from the UE to the BBU.
As connection between the BBU and the RRH, in order to efficiently provide a number of small cells, a centralized radio access network (C-RAN) configuration is implemented in which a plurality of BBUs are integrated into one unit and each BBU is connected to an RRH on a one-to-one basis using an optical fiber.
However, because this C-RAN configuration requires optical fibers in proportion to increase of the number of small cells, cost required for maintaining and laying optical fibers becomes a problem in a small cell connection method in the future.
Therefore, as an economical connection method of a mobile front haul (MFH) (between the BBU and the RRH), utilization of TDM-PON is considered (see Shigeru Kuwano, and others, “Low-Latency DBA for Mobile Optical Network Based on TDM-PON System”, General Conference of the Institute of Electronics, Information and Communication Engineers, 2014, B-8-54 (Non-Patent Literature 1)).
Because, in the TDM-PON, one star-shaped optical fiber is shared among users in time division, it is possible to suppress the required number of optical fibers. Further, because star-shaped optical fibers for FTTH service have been already widely laid in Japan, it is possible to reduce cost for laying optical fibers if unused fibers are utilized.